The present invention relates to a switching mechanism for alarming time detection in an alarming device for use in a clock, a timer, and any other device for telling the time, and being operable to detect a preset alarm time and to transmit a signal to operation effect of a time-telling mechanism or other similar electrical mechanism when the set alarm time is reached.
Generally known thus far is a type of switching mechanism for an alarming device of a clock, for one thing, wherein an aperture is formed at a certain position of a rotationally driven drive wheel and a projection is formed on an alarm time setting wheel such that the projection is caused to fall in the aperture when the time wheel and the alarm time setting wheel are rotated into phase with each other whereby the alarm time setting wheel is displaced to the side of the time wheel by virtue of a spring, and the motion of the displacement of the alarm time setting wheel causes a switch to be closed. However, in such a conventional mechanism, the spring action is applied on the time wheel at all times and such is disadvantageous in that the driving energy source (for instance, a motor) of the time wheel has a surplus load unduly applied thereon. In addition, the surface of the projection, in order to fall into the aperture, is so formed as to be vertical for the purpose of improving the precision of alarm time detection, and the alarm time setting wheel cannot but be revolved only in a single direction in the case of turning the alarm time setting wheel for setting anew a different alarm time. These constructional limitations have proven quite inconvenient in the use of the conventional switching mechanism.
The present invention has been devised for the purpose of eliminating the foregoing disadvantages of the conventional switching mechanism, and for providing a new switching mechanism for alarm time detection which is capable of achieving a new effect.
A detailed description of the present invention will be given below, by making reference to the drawings attached hereto to show an illustration of several embodiments of the invention switching mechanism for alarm time detection in the state of being employed in the alarming device of a clock .